Thread: string name = 'JOHN';

Hi

I have seen someone using string in this way. Perhaps I'm using wrong syntax. Please tell me where I'm going wrong. Thanks a lot.

Code:

#include <iostream>
#include <cstdlib>
#include <string>

using namespace std;

int main()

{
string name = 'JOHN';

cout << name;

system ("pause");

}

Originally Posted by inequity

For any null terminated strings, which is what you're setting the string to match, you want to use double quotes. Single quotes are generally used for single characters.

This syntax would work

Code:

string name = "JOHN";

Thanks a lot, inequity. It does work. I don't even need the header file #include<string>. By the way, could you please tell me what the difference is between normal string and 'null terminated' string? Thank you.

Originally Posted by jackson6612

I don't even need the header file #include<string>.

Yes you do. Your code is not guaranteed to work without it. It could, for example, break next time you update your compiler.

With your current compiler and library you have just gotten lucky - one of the other header files you are #include'ing happens to #include <string>. That is not forbidden, but it cannot be relied on.

Originally Posted by threahdead

C++ automatically adds a terminating null byte to the end of "text" for example. In this case a normal and null terminated string is the same, although you should be aware that strings and character arrays like "text", are not the same.

Btw, you should include <string> always when you use std::string.

Thank you, threahdead, grumpy. Thanks for pointing this out to always include the header file. What is the purpose of adding null byte at the end? Could you please tell me?

Although this may sound a stupid question, I'm having difficulty understanding how to enter "JOHN" in such a way that it could be displayed (or, couted) several times using the for loop?

I tried to enter it this way:

Code:

char v;
cout << "Enter the name: ";
cin >> v; // v is entered as 'JOHN'
cout << v << endl; //only 'J' is displayed.

Please help me.

Best wishes
Jackson

Originally Posted by jackson6612

What is the purpose of adding null byte at the end?

It is a marker (also called a sentinel) that identifies the end of the string.

Originally Posted by threahdead

You read the input into a single byte (one chararacter).
Replace char with string and then it should work as desired.

Thanks both of you, grumpy, threahdead.

I haven't learned of the string so far. I only know of this because I remember some member used it. But today the instructor asked us to write a code so that your name in capital letters is printed a certain number of times using the for loop. I was wondering how this could be done without using the declaration string because the instructor didn't teach us anything about the string so far. Please tell me. Thanks.

Thanks a lot. Well the funny thing is that he hasn't taught us anything on character arrays too. So how do I do it using some 'elementary' approach?

You can print them character by character:

Code:

for (int i = 0; i < 10; ++i)
{
    std::cout << 'J' << 'O' << 'H' << 'N' << std::endl;
}

Originally Posted by kmdv

You can print them character by character:

Code:

for (int i = 0; i < 10; ++i)
{
    std::cout << 'J' << 'O' << 'H' << 'N' << std::endl;
}

Thanks, threahdead, kmdv.

kmdv, your suggestions solved the problem and I'm sure this is what the instructor wanted from us.

Best regards
Jackson

Originally Posted by threahdead

Using character arrays is the basic approach

I would argue the elementary approach in C++ is to use std::string.